[Homology analysis and clinical infection characteristics of hypervirulent Klebsiella pneumonia].

Objective: The hvKP phenotype strains were screened from the sensitive and multi-drug resistant Klebsiella pneumoniae, and the distribution and homology of their clinical infection characteristics were compared. Methods: A total of 158 Klebsiella pneumoniae strains isolated from clinical infection specimens in the Third Affiliated Hospital of Sun Yat-sen University from 2014 to 2018 were retrospectively collected. The string test (ST) was used to screen the hvKP infection, and a total of 65 were screened. The number of patients included 51 males and 14 females, with an average age of 56 years. The composition ratio of Klebsiella pneumoniae was analyzed for clinical infection related information. Matrix assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) was used to identify the hypervirulent Klebsiella pneumoniae and establish a new database, and bio-tree cluster analysis and principal component analysis were carried out for all strains that met the experimental conditions by using analysis software and the homology of protein level was obtained. Results: A total of 65 strains hvKP were screened, 62 of which were susceptible strains and 3 were multi-drug resistant strains. The main diseases of infected patients were diagnosed as hepatobiliary disease, encephalopathy and liver abscess. The basic diseases of the population were mainly diabetes and hypertension. Dendrogram cluster analysis divided hvKP into 3 groups at a distance of 550 from the horizontal line; principal component analysis found that some strains were closely related, and the Kc group with the largest proportion was mainly related to hepatobiliary diseases. Ka group was mainly related to infection after surgery. Conclusions: HvKP was highly invasive and the clinical manifestations of infection were diverse. The infected patients were mostly elderly patients with weakened immunity. The rapid homology analysis of MALDI-TOF MS mass spectrometry has important clinical significance for the rapid screening of hvKP infection.

Gill tissue lipids of salmon (Salmo salar L.) presmolts and smolts from anadromous and landlocked populations.

Composition of membrane lipids from the gills of juvenile Atlantic salmon (Salmo salar) in presmolt and smolt phases of development was compared among anadromous and non-anadromous populations. Three stocks migrating from spawning rivers to either lake (landlocked stock), brackish water or full strength sea water were grown under common garden conditions, and gill lipids and their acyl and alkenyl chains were examined in February (presmolts) and at the end of May (smolts) by mass spectrometry and gas-liquid chromatography. The most remarkable changes upon transition from the presmolt phase to the smolt phase were: (i) increase in the cholesterol/phospholipid ratio, (ii) decrease in the abundance of phosphatidylinositol (PI) content, (iii) increase in the amount of sulfatides, (iv) increase in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) species with two highly unsaturated acyl chains, and finally (v) convergence of interstock differences in PC and PE species composition towards a similar lipid composition. Increases in the gill membrane content of cholesterol and sulfatides are discussed as pre-adaptation of salmon gills for salt-secretion, which may occur by increases in membrane microdomains (rafts) harboring ion channels and pumps. The decreases of PI were likely related to adjusting the gill membrane permeability to ions by diminishing prostanoid production. The similarity of those changes among three salmon stocks and the convergence of initially (presmolt phase) different PC and PE species profiles between the stocks towards similar lipid composition suggests that smoltification process of the gill epithelium is largely similar in anadromous and landlocked populations.

Inhibition effect of silver nanoparticles on herpes simplex virus 2.

The herpes simplex virus 2 (HSV-2) is one of the most important sexually transmitted pathogens, and can facilitate the spread of human immunodeficiency virus. The currently available antiviral drugs have certain limitations. Nanosilver has received increasing attention recently with respect to its antibacterial and antiviral properties. The purpose of this study was to determine the inhibiting effect and mechanism of silver nanoparticles (Ag-NPs) on HSV-2. The cytotoxicity of Vero cells induced by different Ag-NP concentrations was investigated by using the methyl thiazolyl tetrazolium (MTT) assay. The inhibiting effect of Ag-NPs on HSV-2 at various times was also evaluated by using a plaque assay. The toxicity of 100 µg/mL Ag-NPs on Vero cells was very low. The mixture of Ag-NP suspension and HSV-2 prior to infecting cells could significantly inhibit the production of progeny viruses. Ag-NPs also inhibited the replication of HSV-2 for 24 h before infecting cells with HSV-2. Therefore, 100 µg/mL Ag-NPs could completely inhibit HSV-2 replication. Ag-NPs at nontoxic concentrations were capable of inhibiting HSV-2 replication when administered prior to viral infection or soon after initial virus exposure. This suggests that the mode of action of Ag-Nps occurs during the early phases of viral replication.

[Identification of Chinese herbs in the Qing Royals--Fu Shen and Fu Shen Mu].

The use of Fu Shen and Fu Shen Mu as medicines has had a long history. Today Fu Shen is still taken as bulk medicinal materials, whereas Fu Shen Mu had disappeared in the medical market. Fu Shen, Yun Fu Shen, Bai Fu Shen, and Bao Mu Fu Shen were used in clinical application in the Qing Royals. Bai Fu Shen and Fu Shen Mu are still kept as speciment in the Palace Museum today. It was found that Bai Fu Shen in the Qing Royals was the same as Fu Shen after peeling and pine roots recorded in the herbal literatures of the Ming and Qing dynasties, with their character tests and historical analysis. It can be inferred that Fu Shen, Yun Fu Shen and Bai Fu Shen recorded in the Qing Royals were actually Fu Shen, with pine roots in sclerotia and after peeling and pine roots removed in processing. Bao Mu Fu Shen and Bao Fu Shen should refer to Fu Shen with pine roots. Fu Shen Mu should mean Fu Shen without white sclerotia and peel during processing. Fu Shen, currently used clinically, is Bao Mu Fu Shen in the Qing Dynasty. Fu Shen distinguishes greatly from Fu Shen Mu in their effects. Such identification and analysis of herbs provides a way of thinking for further hurb studies of the Qing Dynasty.

[The necessity of post-maneuver postural restriction in treating posterior canal benign paroxysmal positional vertigo: a Meta-analytic study].

Objective: We conducted a Meta-analysis to investigate the necessity of postural restrictions after manual reduction in the treatment of posterior canal benign paroxysmal positional vertigo (PC-BPPV). Methods: We searched PubMed, EBSCO, Proquest, Web of Science databases, Ovid, and screened eligible studies that investigated the effect of post-maneuver postural restriction in treating patients with PC-BPPV. Outcomes included the efficacy of treatment and recurrence. Meta-analysis was performed using Stata 15.0 software. Results: Studies of the single visit efficiency included 11 references, with a sample size of 1 733 cases. The Meta-analysis results showed that the difference in the efficacy between the postural restricted group and the non-postural restricted group in PC-BPPV patients was statistically significant(RR=1.12, 95%CI=1.07-1.18, P<0.001). There were 12 references included in the study on the total efficiency, with a cumulative sample size of 1763 cases. There was no statistically significant difference between the effect of postural restriction after manipulative reduction and that of simple manipulative reduction (RR=1.03, 95%CI=0.99-1.08, P=0.118). There were 5 references included in the study of recurrence rate, and the cumulative sample size was 659 cases. There was no statistically significant difference in the recurrence rate between the postural restricted group and the non-postural restricted group(RR=0.98, 95%CI=0.62-1.54, P=0.937). Conclusions: In comparison with non-postural restriction group, post-maneuver postural restriction after a single visit can improve the treatment effective rate of PC-BPPV and contribute to the improvement in the symptoms of patients in a short term. However, postural restrictions has no significant effect on the final prognosis of PC-BPPV, and it also has no significant effect on the recurrence.

Sequential releasing of VEGF and BMP-2 in hydroxyapatite collagen scaffolds for bone tissue engineering: Design and characterization.

The property of biomaterials to control the sequential release of growth factors has been widely concerned in the field of bone repair and regeneration. Double-factor sustained-release scaffolds have good biocompatibility and bioactivity. O­Carboxymethyl chitosan microspheres (O-CMCS) has antimicrobial activity, biodegradability, biocompatibility and film formation. This study developed scaffolds materials with microspheres with a purpose of forming a controlled slow release secondary structure. O-CMCS were used as drug carrier to construct the compound sustained-release system with rhBMP-2 and VEGF double factors release. The O-CMCS were loaded with rhBMP-2 and the hydroxyapatite collagen (HC) scaffolds were loaded with VEGF to prepare the scaffolds. These were double factors composite sustained-release system scaffolds. The biocompatibility of the sustained-release system was evaluated by in vitro and in vivo experiments. HC composite scaffolds were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction detection (XRD), in vitro sustained release test, in vitro cell culture and in vivo animal experiments. The results showed that rhBMP-2/VEGF in HC composite scaffolds (HCBV) successfully achieved the sequential release of the double factors, which could benefit bone regeneration.

Radio frequency measurement and tuning of a 13 MeV Alvarez-type drift tube linac for a compact pulsed hadron source.

This paper describes the radio frequency (RF) measurement and tuning result of a 13 MeV Alvarez-type drift tube linac (DTL) for a compact pulsed hadron source (CPHS) at Tsinghua University. The design, machining, assembly, and alignment of the DTL are presented for integrity. The CPHS project consists of a high-current proton linac (13 MeV, 16 kW, peak current of 50 mA, 0.5 ms pulse width at 50 Hz), a neutron target station, a small-angle neutron scattering instrument, and a neutron imaging/radiology station. The linac contains an electron cyclotron resonance ion source, a low energy beam transport line, a four-vane radio frequency quadrupole (RFQ) accelerator, an Alvarez-type DTL, a high energy beam transport line, and a RF power supply and distributor. Construction on the CPHS started in June 2009, and the CPHS has provided 2000 h since 2013 to users with the neutrons produced by the 3 MeV proton beam from the radio frequency quadrupole bombarding on the beryllium target as an achievement of its mid-term objective. Presently, the tuning of the assembled DTL cavity has been completed successfully. The 4.3-m-long DTL consists of 40 accelerating cells, among which 39 full-length drift tubes (DTs) are suspended inside the cavity, and two half-length DTs are mounted inside the two end flanges of the cavity. Each DT contains a permanent magnet quadrupole. Thirteen post couplers and nine tuners are available for the tuning of the field. The relative error of the field after tuning is within ±1.6%, with a tilt sensitivity within ±33%/MHz in all cells. The beam energy will reach its designed value of 13 MeV after the DTL is installed in the beam line downstream the 3 MeV RFQ accelerator.

[A 2-year cohort study on the caries risk assessment of 3-year-old caries-free children using Cariostat caries activity test].

Objective: To evaluate the caries status of a cohort of 3-year-old caries-free children from 2 kindergartens in Beijing in a period of 2 years by using Cariostat caries activity test and to assess the sensitivity and specificity of Cariostat score as a caries risk indicator for caries-free children. Methods: Totally 426 3-year-old caries-free children from 2 kindergartens in Beijing were recruited in the present study. Informed consents were obtained from the children's parents. Dental plaque samples of the children were collected and the Cariostat caries activity tests were conducted at baseline and once a year for 2 years. After two years, the caries status of the cohort children were re-evaluated and the caries incidences amongst children with high (2.0, 2.5, 3.0), medium (1.5) and low (1.0, 0.5, 0.0) levels of Cariostat scores were compared and analyzed. Results: Totally 864 3-year-old children from 2 kindergartens were screened before the study startedand 426 (49.3%) children were caries free. After 2-year follow-up, 312 out of 426 (73.2%) remained in the study. The overall caries incident rate was 46.5% (145/312). The caries incident rate of children with high level of Cariostat scores was 88.9% (88/99), while the caries incident rates of children with medium and low levels of Cariostat scores was 38.7% (36/93) and 17.5% (21/120), respectively. The sensitivity and specificity of the Cariostat test in assessing the caries risk of 3-year-old caries-free children in a period of 2 years were 60.7% and 93.4%, respectively. Conclusions: Cariostat caries activity test can be used as an indicator to predict the caries risk of 3-year-old caries-free children. Comprehensive caries management could be conducted for children in kindergartens based on the caries risk assessment results of caries experience and the Cariostat score.

Soft tissue chondroma of the parapharyngeal space: a case report.

Benign chondroma affecting the soft tissues is uncommon. This tumour is particularly rare in the neck. We present the first case of soft tissue chondroma arising in the parapharyngeal space of a 20-year-old man with a two-year history of a gradual sensation of a swelling in the pharynx with increasing snoring. The CT and pathological features of this lesion will be discussed. We suggest that a peroral approach should be considered for benign parapharyngeal tumour which has been demonstrated on imaging to be in the anterior parapharyngeal space, especially for tumours that are medial to the pterygoid muscles even though the tumour is a large one.

Compensatory caspase activation in MPP+-induced cell death in dopaminergic neurons.

Many have hypothesized that cell death in Parkinson's disease is via apoptosis and, specifically, by the mitochondrial-mediated apoptotic pathway. We tested this hypothesis using a mouse dopaminergic cell line of mesencephalic origin, MN9D, challenged with the Parkinsonism-causing neurotoxin MPP+ (1-methyl-4-phenylpyridinium ion). Apoptosis was the main mode of cell death when the cells were subjected to MPP+ treatment under serum-free conditions for 24 h. Caspase-3 and caspase-9, however, were not activated, thus indicating the existence of alternate or compensatory cell death pathway(s) in dopaminergic neuronal cells. Using caspase inhibitors, we demonstrated that these pathways involve caspase-2, -8, -6 and -7. A time-course study indicated that activation of caspase-2 and -8 occurred upstream of caspase-6 and caspase-7. Upon MPP+ challenge, the apoptosis-inducing factor was translocated from the mitochondria into the MN9D cytosol and nucleus. These results suggest the existence of alternative apoptotic pathways in dopaminergic neurons.